Aircraft having sustaining rotors



June 4, 1935. H. ALFARO 2,003,620

AIRCRAFT H AVING SUS'I'AINING ROTORS I Original Filed Dec. 9, 1931 3 Sheets-Sheet 1 INVEN OR AT RNEYS June 4, 1935. H. ALFARO 2,003,620

I AIRCRAFT HAVING SU$TAINING ROTORS I Original Filed Dec. '9, 1931 s Sheets-Sheet 2 E EZ Qr June 4, 1935. H. ALFARO 2,003,020

AIRCRAFT HAVING SUSTAINING ROTORS Original Filed Dec. 9, 1931 3 Sheets-Sheet 3 INVENTOR 7 Awzk 67 66 ATT RNEY3 Patented June 4, 1935 UNITED STATES I 2,003,620 .amcaarr navme sus'ramme no'rons Heraclio Alfaro, Cambridge, Mass., assignor to Autogiro Company of America, Philadelphia, 1 Pa., a corporation of Delaware Original application December 9, 1931, Serial No. 579,853. Divided and this application May 24,

1934, Serial No. 727,245

"as indicated in Figure v1, serve to support the 4 Claims.

This invention relates to aircraft having sustaining rotors and is more particularly concerned with the type of craft in which the sustaining rotor is composed of a plurality of sustaining blades or wings mounted for rotation about a common substantially vertically extended axis and also for individual movements with the rotativesustaining wings or blades.

respect to the rotoraxis structure in order to compensate for variationsin flight forces.

More specifically the invention has reference to an improved means for adjustably mounting Still further it is the object of the invention to provide an efiective and yet very simple device by. means of which the wing or blade incidence may be adjusted.

Other more or less general objects and ad-' vantages contemplated by. this invention include ing reference to the accompanying drawings in which-,

Figure 1 is a side elevational view of a craft constructed to embody various novel features of this invention including the adjustable blade mounting hereinbefore referred to;

Figure 2 is a vertical sectional view through the rotor hub or head structure, this viewalso including portions of the mounting structure for the rotor system;

Figure 3 is a horizontal sectional view taken substantially as indicated by the section line 33 on Figure 2; and

Figure 4is a sectional view taken as indicated by the section line 44 on Figure 2.

It should first be noted that in Figure l'the craft illustrated includes a fuselage H having an empennage l2 and an engine and propeller l3ll. Supplemental fixed lifting surfaces l5 may be extended laterally at the sides of the craft and suitable landing gear l6 as well as a tail skid ll serve to support the craft onAahe ground.

The fuselage II is provided with a. pair of cockpits l8l9 over the forward one of which (It) the rotor system is mounted. For the purpose of mounting the rotor I prefer to employ a plurality of leg elements '2l2l which,

rotor hub, generally indicated by the reference numeral 23. An upward extension 24 of the hub 23 serves as a point. of attachment of theblade supporting cables 25, these cables being provided in order to prevent the blades from drooping unduly-when the rotor is not operating at flight speeds or when the rotor is at rest.

As shown in Figure 1-, the rotor system itself composed pf a plurality of wings or blades 26 which are mounted for rotation, under the action of relative air flow, about the axis of the mechanism 23 and which are also pivotally attached to such mechanism as by means of vertically and horizontally extended pivot pins 27 and 2B.

As seen in Figure 2, the rotor head may be by means of a plate'32 and bolts 4|. The rotor head includes a normally fixed hub base 36 which is centrally apertured to receive spindle 37 projecting upwardly and surrounded by radial bearings 4545 as well as a thrust bearing 54, all of these bearings being in turn surrounded by the rotatable hub member 44 on which the blades are mounted. The thrust of sustension of the craft is transmitted from the blade mounting hub member 44 through the thrust bearing 54 to the central tie member or bolt 38 from which the thrust is carried supported at the top or" the posts 20 and 2| downwardly to the fixed hub base 36 and thence to the supporting posts 20 and 2|.

The mechanism illustrated in the drawings also includes a rotor braking and rotor driving means and while these parts need not be considered in detail herein, it is noted that a drive shaft 30 (see Figures 1 and 2) extends upwardly from the body of the craft preferably from the engine I3, to connect with a pinion '82 which is adapted to mesh with the internal ring gear 16 carried by the downturned drum 14 which is, in turn, carried by the rotatable,

cylindrical portion of drum 14, a fragment of this band being illustrated at 8'l in; Figure -2.

For the purpose of attaching the individual blades to the rotor hub ,this hub member is provided with pairs of verticallyspaced. and

vertically apertured lugs into which the vertically extended individual blade pivot pins 21 are inserted, said lugs being easily and conveniently formed by squaring ofi the flange members which are shown at 630 in Figure 3.

Each of the blades is secured to its vertical pivot .pin 21 in substantially the following -manner I plementary bracket members -65 to be embraced thereby. 'At its inner end, the blade spar fitting 66 is further provided with a squared block 61 which may conveniently abut against the base of the root fitting 6565 in the manner clearly illustrated in Figure 2. After assembly of these parts a split securing or fastening ring 686 8 is applied to the two parts of the fitting 65-65 and rigidly tightened thereon as by means of the bolt 69.. halves of the ring 68-68 are, of course, pivoted to each other at a point diametrically opposite to the bolt 69 as by means of a pivot pin 10. l

In order to provide for adjustment of .the

incidence of the individual blades, I prefer to employ adjusting bolts 'Il arranged at four corners of the squared block 61 and taking into the fork parts of the brackets 65-65. The disposition of these adjusting parts in the manner just described provides for an extremely simple blade incidence adjustment, all the parts of which are compactly arranged as well as disposed in 'such manner as to utilize space between the bracket members 65-65. The frontal area and weight of these various parts is thus kept very small.

It might also be mentioned that theblade mounting structure as shown in Figure 3, includes projecting bracket members 12 between which and the hub member 44 itself resilient or rubber blocks 13 are inserted for the purpose of yieldingly resisting blade movement about the upright blade articulations 21.

From the foregoing it will-be seen that all The two of the rotor hub and blade mounting parts sooperate neatly to provide a compact rotor head assembly and further that all of these parts, including the incidence adjustment mechanism, are of such form or character that they may readily befabricated. The use of a split fitting for the blade root is also of advantage in simplifying as well as reducing the weight and size of therotor head in general, especially in view of the incorporation ther'ein of the incidence adjusting mechanism for the blades.

This application is a division of my copending application Serial No. 579,853 filed December 9th, 1931.

What I claim is:-

1. In an air driven rotor system, an axis mechanism, a rotor blade mounted on the axis mechanism, and means for adjusting the incidence of said blade, said means including a squared device fixed at the blade root, bracket means at opposite sides of the squared device and adjusting elements operatively associated with the said device and the bracketmeans to alter their relative angular positions.

2. In-an air driven rotor system, an axis .mechanism, a rotor blade mounted on the axis -mechanism, and means for adjusting the mci- -dence of said blade, said means including a squared device fixed at the blade root, bracket means at opposite sides of the squared device and adjusting bolts taking'into the bracket means and arranged to react against corner portions of said device.

3. In an air driven rotor system, an axis mechanism, a rotor blade mounted on the'axis mechanism, and means for mounting the said blade including a pivot pin, a forked device cooperating with the pin, an abutment fixed at the root of the blade and positionedbetween the forks of said device adjacent the base thereof, and means reacting between said forks and said abutment for adjusting the incidence of the blade.

4. man air driven rotor .system, an axismechanism, a rotor blade mounted on the .axis' .between the forks of said fitting and arranged to react between the fitting and the blade root.

HERACLIQ ALFARO. 

